By John W. Conover IV
Although it's the time of year when leaves start falling, energy prices will continue to rise. According to the U.S. Department of Energy, this winter will bring more increases in costs of oil, electricity, and natural gas.
As facility managers anticipate energy rate hikes, storms, cold spells, equipment freeze-ups, brownouts, and other possible wintertime conditions, they can take measures to ensure their buildings maintain optimal energy efficiency and operating performance. The transition from the cooling to heating season is a great time to take a thorough "inside-out" look at building systems to detect and resolve problems before they become major cost or comfort issues.
Don't Let Heating Costs Go Through the Roof
During the summer, facility managers prepared their building systems for the heating season and perhaps made investments in repairs or upgrades. Yet, HVAC systems in the best condition may perform poorly due to other problems in the building. Heat loss often occurs due to air leaking through the building envelope or conduction through poorly insulated walls. Simple diagnostic tests can unearth hidden troubles, such as a leaky roof or ductwork, or worn components that diminish system operation and efficiency.
Infrared thermography is an inexpensive, easy-to-use tool to detect building and system heat loss. Options include hiring a professional thermographer or renting a thermal imager, which takes only an hour or two to learn how to use. The thermal imager detects and graphically displays changes in heat patterns and temperature changes in objects.
It can reveal problems such as:
- Insulation gaps.
- Roof leaks.
- Heat loss through damaged window or door seals.
- Damaged heat ducts.
- Steam line leaks.
- Equipment wear.
Thermography can also detect moisture problems that cause mold. Since moist insulation has greater heat capacity than dry insulation, it will show up on the imager. Infrared allows the facility manager to pinpoint and remediate heat-loss problems before the cold weather sets in.
Fall Building Checkup
High-performance buildings maintain life-cycle building efficiency. This requires a proactive approach to maintenance throughout the year. Facility managers using a task-based maintenance approach should consider the benefits of preventive and predictive programs.
Preventive maintenance is based on time- or schedule-based tasks to prevent or mitigate system and component degradation and prolong equipment life-cycle. Predictive maintenance bases maintenance on actual condition of the equipment, detecting possible problems or inefficiencies before they occur.
FEMP reports that a predictive program can reduce maintenance costs by 25 to 30 percent, eliminate breakdowns by 70 to 75 percent, and reduce downtime by 35 to 45 percent.
Any proactive maintenance program starts by documenting the objectives of the building's stakeholders, such as management, occupants, and facility staff. Once current building system conditions are evaluated, they are compared to the organization's goals. Then, a maintenance plan is designed to reach the desired outcomes, such as reducing energy consumption and operating costs, and improving indoor conditions.
Proactive maintenance includes seasonal evaluations to find existing and potential trouble spots or "gaps" that may undermine system performance.
Items to consider for fall maintenance inspection:
- Test all heating equipment, including boilers, heat exchangers, and steam distribution.
- Inspect roof, windows, weatherstripping, and doors for leaks.
- Inspect electrical, plumping, and piping systems.
- Verify control schedules and setpoints for fall schedule and occupancy.
- Recalibrate all sensors for temperature, humidity, and air flow.
- Check heat transfer and pressure levels to assure that the HVAC system is performing optimally.
- Check ventilation distribution systems and perform basic IAQ testing, including humidity levels.
Facility managers cannot predict the winter weather, but they can take steps to stay on target with energy-efficiency goals, regardless of outdoor conditions. OSHA recommends indoor temperatures in the range of 68 to 76 degrees F. Keeping temperatures within this range helps ensure comfort and health of occupants.
Here are a few tips for maintaining indoor comfort without sky-high utility bills:
- Reduce heating in spaces that are not used or are used only for short periods of time.
- Preheat spaces gradually to achieve proper temperature by the time occupants arrive, considering that lighting, office equipment, and people will also increase the temperature a few degrees.
- Make sure exhaust fans are working properly so that they do not exhaust more air from the building than intended.
- Minimize overheating due to poor zoning, poor distribution, or improper location of sensors, such as near drafts.
If a building fails to maintain temperature or humidity requirements, experiences a sudden increase in energy use, or is undergoing modifications, retrocommissioning may be in order. Many buildings that were fully commissioned when they were built no longer operate at peak efficiency.
Retrocommissioning involves comprehensive testing of building systems to determine where improvements are needed. It typically includes the HVAC system, and may include the building envelope, electrical, lighting, plumbing, and safety systems.
- Identifying overall facility goals, including productivity, occupant safety and health, and energy efficiency.
- Evaluating and documenting building systems' operation and performance.
- Comparing current system performance with facility requirements and energy-efficiency targets.
- Identifying problems in systems, equipment, or components.
- Benchmarking current system performance.
- Targeting ways to increase systems' energy efficiency.
The retrocommisiong project can also be designed to evaluate facility performance against LEED-EB standards, allowing building operators and managers to determine which investments will be most cost effective to improve building systems. Once retrocommissioning data are collected, they can be compared against changing equipment performance. This helps facility management to achieve high-performance for the building's life-cycle.
Seasonal Energy Management
High-performance energy management includes regular evaluation of utility contracts and constantly finding ways to reduce energy costs. One way to secure more favorable retail energy contracts is by keeping the building's load demand as level as possible through the wintertime. Many electric utilities offer lower rates during off-peak periods (typically at night).
Perform a rate analysis on all utility meters and diminish non-critical loads at peak periods to prevent temporary electrical demands from creating higher annual energy bills. For example, peak usage spikes could be due to charging up equipment or the use of space heaters.
In the fall, also review summer energy performance to see if there are opportunities to improve efficiency next cooling season. Conduct an audit and a summary of the heat index over the summer, and evaluate power consumption targets and peak demands.
There's no better time than now for facility managers to get their buildings on track for a high-performance winter.
John W. Conover IV is the president of Trane's commercial systems business in the Americas region.